抛光垫使用寿命对铜CMP平均去除速率一致性的影响  

Effect of Polishing Pad Lifetime on the Average Removal Rate Uniformity of Copper During CMP

作　　者：江自超 刘玉岭 王辰伟 张凯 

机构地区：[1]河北工业大学电子信息工程学院,天津300130 [2]天津市电子材料与器件重点实验室,天津300130

出　　处：《微纳电子技术》2017年第10期715-719,共5页Micronanoelectronic Technology

基　　金：国家中长期科技发展规划重大专项资助项目(2009ZX02308);集成电路碱性抛光液与清洗液的研发资助项目(2016ZX02301003-004-007);河北省自然科学基金青年基金资助项目(F2015202267);天津市自然科学基金资助项目(16JCYBJC16100);河北工业大学优秀青年科技创新基金资助项目(2015007)

摘　　要：针对抛光垫的使用寿命对铜膜平均去除速率一致性的影响进行研究,同时采用实时表面形貌控制(RTPC)技术,对抛光过程中,铜膜表面形貌进行实时监控。实验结果表明:抛光垫的使用寿命对铜膜化学机械抛光(CMP)平均去除速率影响很大,使用前期(抛光垫使用时间Tt≤500 pcs),铜膜平均去除速率稳定,粗抛一致性良好(片内非均匀性(WIWNU)为3.37%),粗抛后剩余膜厚范围小于60 nm。使用后期(Tt>500 pcs),粗抛速率一致性较差,粗抛后剩余膜厚范围大于100 nm。抛光垫修整能有效恢复抛光垫表面状态,采用在线同步修整技术,可以延长抛光垫使用寿命到750 pcs以上。但是过长的修整时间不能保证铜膜良好的平均去除速率一致性,也会加大抛光垫磨损,降低使用寿命。The effect of polishing pad lifetime on the average removal rate uniformity of copper film was studied. And the real time profile control （RTPC） technology was adopted to monitor the morphology of copper film in real time during the polishing process. The experimental result shows that the lifetime of polishing pad has a great effect on the average removal rate of copper film during chemical mechanical polishing （CMP）. The average removal rate of copper film is sta- ble when the polishing pad is used in early period （the polishing pad lifetime Tt≤500 pcs）. The with-in-wafer-non-uniformity （WIWNU） is 3.37% during rough polishing, and the remaining thickness range of the copper film is less than 60 nm after rough polishing. However, the remo- val rate uniformity of copper film during rough polishing is poor in late period （Tt〉500 pcs）, and the remaining thickness range of the copper film is more than 100 nm after rough polishing. The pad condition can effectively restore the surface state of polishing pad, and the online syn- chronous condition technology can extend the polishing pad lifetime to 750 pcs or more. However, longer condition time cannot guarantee a good average removal rate uniformity of cop- per film, and can increase the polishing pad wear and reduce the polishing lifetime.

关 键 词：抛光垫 使用寿命 实时表面形貌控制(RTPC)技术 平均去除速率一致性 同步在线修整 

分 类 号：TN305.2[电子电信—物理电子学]